Protect neighbor from piano. $$$ plan failed. How to address window seat?

[moneypit]

Hello!
Condo, small room.  All walls and ceiling are adjacent to my own rooms.
Floor is above a quiet neighbor and I am trying to protect her from my new piano.
It was a big expensive undertaking and now we discover that it has failed.

Steps already taken:
1. Hardwood floor ripped out.  12mm Ecore underlayment installed, with Bostik sound-deadening glue above and below it.  New hardwood floor on top.
2. 8x10 rug covering majority of room, with thick memory-foam rug pad.
3. Piano placed on caster cups designed to isolate vibrations from floor.

After all this expensive work was done, We tested it again.  The sound of the piano is still very present in the downstair's neighbor's room.  I am absolutely dejected.

Voices did not transmit, and or course the lower tones transmitted most of all.

So this brings me to my present question:

There is a large window seat right next to the low end of the piano, which was not addressed.  Soundproofing expert returned and said that the window seat cavity may be hollow.  He recommended that I open it up, fill it with a couple layers of mineral wool, and re-install that flooring.

Will this work?

It's so discouraging to have all this expensive work done, and to wait the many months for it to get done, and then to have it seem to make almost no difference. 

Attached is a photograph from the side of the window seat, whose top is about 18"x74".

I earnestly seek your advice, and I thank you in advance for your consideration.

[Randy S]

By simply soundproofing the floor does not stop flanking noise from the 4 walls in the room sending sound to the downstairs neighbor..

What I do not see is decoupling for low frequency and lots and lots off Mass....

ecore is for footfall and impact but is not going to perform as you would expect for low frequency..

simply addressing the window seat I highly doubt would improve the overall results.

You are not dealing with just " impact / footfall" you are generating ambient sound waves which will deliver some vibration through the legs of the piano but that is minor compared to the size of the sound waves from the piano... look at it like hitting the entire room with a sledge hammer...thats what you are creating...

This requires far more attention to decoupling and mass.

Feel free to give me a call direct.

Randy S.
760-752-3030

[moneypit]

Randy, thank you so much for your reply.

I would imagine that you would say there is no way to truly address this without actually opening up the walls. Is that true?

We are planning to put up melamine tiles on a portion of all walls. I understand that this doesn't decouple— but your description of sound waves hitting the entire room— will the tiles at least absorb some of the waves and thereby prevent them from traveling?

I guess what I'm saying is that we aren't in a position to open up the walls, and that we are willing to live with a situation that is not completely soundproofed. But we wanted the improvement to be more substantial than it has been so far.

So, within those parameters— do you think that the absorption on the walls can make any significant difference?

Again, thank you so much.

[Randy S]

Moneypit,

Without decoupling your chances of reducing low frequencies becomes minimal, which would require opening the walls or take a risk on a triple leaf system (which I personally do not like to do)

As for the absorption aspect, yes if you address corners and cover the majority of the walls you would reduce some of the sound pressure levels and therefore reducing some of the transmission..

The real question would be how thick would you need to go to see cost vs reduction..

See when doing room acoustics you do not need to get so thick because you are essentially tuning the room, but if you are trying to get "soundproofing" out of acoustic conditioning this changes the game a bit and requires thicker material and far more surface area coverage...

Randy S.

[moneypit]

Randy, this is such helpful information. Thank you so much.

The tiles that the company was intending to install are listed as:
2’x2’x 1.5” white beveled edge class A fire rated Melamine Foam Tiles

So that's 1.5" thickness.

Do you carry thicker products that you feel would give me more assistance with soundproofing than these melamine tiles, as you described?

[Randy S]

These sound like T-bar ceiling tiles...

Are you handy? if so maybe a DIY 4"-6" thick mineral wool or cotton fiber panels.
if you make your own you can add a septum of mass loaded vinyl which would give e bit more help in the low frequencies since you do not have much mass on the walls.

Randy S.